1 //===-- llvm/MC/MCAsmInfo.h - Asm info --------------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains a class to be used as the basis for target specific
11 // asm writers. This class primarily takes care of global printing constants,
12 // which are used in very similar ways across all targets.
14 //===----------------------------------------------------------------------===//
16 #ifndef LLVM_MC_MCASMINFO_H
17 #define LLVM_MC_MCASMINFO_H
19 #include "llvm/MC/MCDirectives.h"
20 #include "llvm/MC/MCDwarf.h"
21 #include "llvm/MC/MachineLocation.h"
32 namespace ExceptionHandling {
33 enum ExceptionsType { None, DwarfCFI, SjLj, ARM, Win64 };
37 enum LCOMMType { NoAlignment, ByteAlignment, Log2Alignment };
40 /// MCAsmInfo - This class is intended to be used as a base class for asm
41 /// properties and features specific to the target.
44 //===------------------------------------------------------------------===//
45 // Properties to be set by the target writer, used to configure asm printer.
48 /// PointerSize - Pointer size in bytes.
52 /// CalleeSaveStackSlotSize - Size of the stack slot reserved for
53 /// callee-saved registers, in bytes.
54 /// Default is same as pointer size.
55 unsigned CalleeSaveStackSlotSize;
57 /// IsLittleEndian - True if target is little endian.
61 /// StackGrowsUp - True if target stack grow up.
65 /// HasSubsectionsViaSymbols - True if this target has the MachO
66 /// .subsections_via_symbols directive.
67 bool HasSubsectionsViaSymbols; // Default is false.
69 /// HasMachoZeroFillDirective - True if this is a MachO target that supports
70 /// the macho-specific .zerofill directive for emitting BSS Symbols.
71 bool HasMachoZeroFillDirective; // Default is false.
73 /// HasMachoTBSSDirective - True if this is a MachO target that supports
74 /// the macho-specific .tbss directive for emitting thread local BSS Symbols
75 bool HasMachoTBSSDirective; // Default is false.
77 /// HasStaticCtorDtorReferenceInStaticMode - True if the compiler should
78 /// emit a ".reference .constructors_used" or ".reference .destructors_used"
79 /// directive after the a static ctor/dtor list. This directive is only
80 /// emitted in Static relocation model.
81 bool HasStaticCtorDtorReferenceInStaticMode; // Default is false.
83 /// LinkerRequiresNonEmptyDwarfLines - True if the linker has a bug and
84 /// requires that the debug_line section be of a minimum size. In practice
85 /// such a linker requires a non-empty line sequence if a file is present.
86 bool LinkerRequiresNonEmptyDwarfLines; // Default to false.
88 /// MaxInstLength - This is the maximum possible length of an instruction,
89 /// which is needed to compute the size of an inline asm.
90 unsigned MaxInstLength; // Defaults to 4.
92 /// MinInstAlignment - Every possible instruction length is a multiple of
93 /// this value. Factored out in .debug_frame and .debug_line.
94 unsigned MinInstAlignment; // Defaults to 1.
96 /// DollarIsPC - The '$' token, when not referencing an identifier or
97 /// constant, refers to the current PC.
98 bool DollarIsPC; // Defaults to false.
100 /// SeparatorString - This string, if specified, is used to separate
101 /// instructions from each other when on the same line.
102 const char *SeparatorString; // Defaults to ';'
104 /// CommentString - This indicates the comment character used by the
106 const char *CommentString; // Defaults to "#"
108 /// LabelSuffix - This is appended to emitted labels.
109 const char *LabelSuffix; // Defaults to ":"
111 /// LabelSuffix - This is appended to emitted labels.
112 const char *DebugLabelSuffix; // Defaults to ":"
114 /// This prefix is used for globals like constant pool entries that are
115 /// completely private to the .s file and should not have names in the .o
117 const char *PrivateGlobalPrefix; // Defaults to "L"
119 /// This prefix is used for symbols that should be passed through the
120 /// assembler but be removed by the linker. This is 'l' on Darwin,
121 /// currently used for some ObjC metadata.
122 /// The default of "" meast that for this system a plain private symbol
124 const char *LinkerPrivateGlobalPrefix; // Defaults to "".
126 /// InlineAsmStart/End - If these are nonempty, they contain a directive to
127 /// emit before and after an inline assembly statement.
128 const char *InlineAsmStart; // Defaults to "#APP\n"
129 const char *InlineAsmEnd; // Defaults to "#NO_APP\n"
131 /// Code16Directive, Code32Directive, Code64Directive - These are assembly
132 /// directives that tells the assembler to interpret the following
133 /// instructions differently.
134 const char *Code16Directive; // Defaults to ".code16"
135 const char *Code32Directive; // Defaults to ".code32"
136 const char *Code64Directive; // Defaults to ".code64"
138 /// AssemblerDialect - Which dialect of an assembler variant to use.
139 unsigned AssemblerDialect; // Defaults to 0
141 /// \brief This is true if the assembler allows @ characters in symbol
142 /// names. Defaults to false.
145 /// UseDataRegionDirectives - This is true if data region markers should
146 /// be printed as ".data_region/.end_data_region" directives. If false,
147 /// use "$d/$a" labels instead.
148 bool UseDataRegionDirectives;
150 //===--- Data Emission Directives -------------------------------------===//
152 /// ZeroDirective - this should be set to the directive used to get some
153 /// number of zero bytes emitted to the current section. Common cases are
154 /// "\t.zero\t" and "\t.space\t". If this is set to null, the
155 /// Data*bitsDirective's will be used to emit zero bytes.
156 const char *ZeroDirective; // Defaults to "\t.zero\t"
158 /// AsciiDirective - This directive allows emission of an ascii string with
159 /// the standard C escape characters embedded into it.
160 const char *AsciiDirective; // Defaults to "\t.ascii\t"
162 /// AscizDirective - If not null, this allows for special handling of
163 /// zero terminated strings on this target. This is commonly supported as
164 /// ".asciz". If a target doesn't support this, it can be set to null.
165 const char *AscizDirective; // Defaults to "\t.asciz\t"
167 /// DataDirectives - These directives are used to output some unit of
168 /// integer data to the current section. If a data directive is set to
169 /// null, smaller data directives will be used to emit the large sizes.
170 const char *Data8bitsDirective; // Defaults to "\t.byte\t"
171 const char *Data16bitsDirective; // Defaults to "\t.short\t"
172 const char *Data32bitsDirective; // Defaults to "\t.long\t"
173 const char *Data64bitsDirective; // Defaults to "\t.quad\t"
175 /// GPRel64Directive - if non-null, a directive that is used to emit a word
176 /// which should be relocated as a 64-bit GP-relative offset, e.g. .gpdword
178 const char *GPRel64Directive; // Defaults to NULL.
180 /// GPRel32Directive - if non-null, a directive that is used to emit a word
181 /// which should be relocated as a 32-bit GP-relative offset, e.g. .gpword
182 /// on Mips or .gprel32 on Alpha.
183 const char *GPRel32Directive; // Defaults to NULL.
185 /// SunStyleELFSectionSwitchSyntax - This is true if this target uses "Sun
186 /// Style" syntax for section switching ("#alloc,#write" etc) instead of the
187 /// normal ELF syntax (,"a,w") in .section directives.
188 bool SunStyleELFSectionSwitchSyntax; // Defaults to false.
190 /// UsesELFSectionDirectiveForBSS - This is true if this target uses ELF
191 /// '.section' directive before the '.bss' one. It's used for PPC/Linux
192 /// which doesn't support the '.bss' directive only.
193 bool UsesELFSectionDirectiveForBSS; // Defaults to false.
195 bool NeedsDwarfSectionOffsetDirective;
197 //===--- Alignment Information ----------------------------------------===//
199 /// AlignmentIsInBytes - If this is true (the default) then the asmprinter
200 /// emits ".align N" directives, where N is the number of bytes to align to.
201 /// Otherwise, it emits ".align log2(N)", e.g. 3 to align to an 8 byte
203 bool AlignmentIsInBytes; // Defaults to true
205 /// TextAlignFillValue - If non-zero, this is used to fill the executable
206 /// space created as the result of a alignment directive.
207 unsigned TextAlignFillValue; // Defaults to 0
209 //===--- Global Variable Emission Directives --------------------------===//
211 /// GlobalDirective - This is the directive used to declare a global entity.
213 const char *GlobalDirective; // Defaults to NULL.
215 /// HasSetDirective - True if the assembler supports the .set directive.
216 bool HasSetDirective; // Defaults to true.
218 /// HasAggressiveSymbolFolding - False if the assembler requires that we use
223 bool HasAggressiveSymbolFolding; // Defaults to true.
225 /// COMMDirectiveAlignmentIsInBytes - True is .comm's and .lcomms optional
226 /// alignment is to be specified in bytes instead of log2(n).
227 bool COMMDirectiveAlignmentIsInBytes; // Defaults to true;
229 /// LCOMMDirectiveAlignment - Describes if the .lcomm directive for the
230 /// target supports an alignment argument and how it is interpreted.
231 LCOMM::LCOMMType LCOMMDirectiveAlignmentType; // Defaults to NoAlignment.
233 /// HasDotTypeDotSizeDirective - True if the target has .type and .size
234 /// directives, this is true for most ELF targets.
235 bool HasDotTypeDotSizeDirective; // Defaults to true.
237 /// HasSingleParameterDotFile - True if the target has a single parameter
238 /// .file directive, this is true for ELF targets.
239 bool HasSingleParameterDotFile; // Defaults to true.
241 /// hasIdentDirective - True if the target has a .ident directive, this is
242 /// true for ELF targets.
243 bool HasIdentDirective; // Defaults to false.
245 /// HasNoDeadStrip - True if this target supports the MachO .no_dead_strip
247 bool HasNoDeadStrip; // Defaults to false.
249 /// WeakRefDirective - This directive, if non-null, is used to declare a
250 /// global as being a weak undefined symbol.
251 const char *WeakRefDirective; // Defaults to NULL.
253 /// True if we have a directive to declare a global as being a weak
255 bool HasWeakDefDirective; // Defaults to false.
257 /// True if we have a directive to declare a global as being a weak
258 /// defined symbol that can be hidden (unexported).
259 bool HasWeakDefCanBeHiddenDirective; // Defaults to false.
261 /// True if we have a .linkonce directive. This is used on cygwin/mingw.
262 bool HasLinkOnceDirective; // Defaults to false.
264 /// HiddenVisibilityAttr - This attribute, if not MCSA_Invalid, is used to
265 /// declare a symbol as having hidden visibility.
266 MCSymbolAttr HiddenVisibilityAttr; // Defaults to MCSA_Hidden.
268 /// HiddenDeclarationVisibilityAttr - This attribute, if not MCSA_Invalid,
269 /// is used to declare an undefined symbol as having hidden visibility.
270 MCSymbolAttr HiddenDeclarationVisibilityAttr; // Defaults to MCSA_Hidden.
273 /// ProtectedVisibilityAttr - This attribute, if not MCSA_Invalid, is used
274 /// to declare a symbol as having protected visibility.
275 MCSymbolAttr ProtectedVisibilityAttr; // Defaults to MCSA_Protected
277 //===--- Dwarf Emission Directives -----------------------------------===//
279 /// HasLEB128 - True if target asm supports leb128 directives.
280 bool HasLEB128; // Defaults to false.
282 /// SupportsDebugInformation - True if target supports emission of debugging
284 bool SupportsDebugInformation; // Defaults to false.
286 /// SupportsExceptionHandling - True if target supports exception handling.
287 ExceptionHandling::ExceptionsType ExceptionsType; // Defaults to None
289 /// DwarfUsesRelocationsAcrossSections - True if Dwarf2 output generally
290 /// uses relocations for references to other .debug_* sections.
291 bool DwarfUsesRelocationsAcrossSections;
293 /// DwarfFDESymbolsUseAbsDiff - true if DWARF FDE symbol reference
294 /// relocations should be replaced by an absolute difference.
295 bool DwarfFDESymbolsUseAbsDiff;
297 /// DwarfRegNumForCFI - True if dwarf register numbers are printed
298 /// instead of symbolic register names in .cfi_* directives.
299 bool DwarfRegNumForCFI; // Defaults to false;
301 /// UseParensForSymbolVariant - True if target uses parens to indicate the
302 /// symbol variant instead of @. For example, foo(plt) instead of foo@plt.
303 bool UseParensForSymbolVariant; // Defaults to false;
305 //===--- Prologue State ----------------------------------------------===//
307 std::vector<MCCFIInstruction> InitialFrameState;
309 //===--- Integrated Assembler State ----------------------------------===//
310 /// Should we use the integrated assembler?
311 /// The integrated assembler should be enabled by default (by the
312 /// constructors) when failing to parse a valid piece of assembly (inline
313 /// or otherwise) is considered a bug. It may then be overridden after
314 /// construction (see LLVMTargetMachine::initAsmInfo()).
315 bool UseIntegratedAssembler;
317 /// Compress DWARF debug sections. Defaults to false.
318 bool CompressDebugSections;
321 explicit MCAsmInfo();
322 virtual ~MCAsmInfo();
324 /// getPointerSize - Get the pointer size in bytes.
325 unsigned getPointerSize() const {
329 /// getCalleeSaveStackSlotSize - Get the callee-saved register stack slot
331 unsigned getCalleeSaveStackSlotSize() const {
332 return CalleeSaveStackSlotSize;
335 /// isLittleEndian - True if the target is little endian.
336 bool isLittleEndian() const {
337 return IsLittleEndian;
340 /// isStackGrowthDirectionUp - True if target stack grow up.
341 bool isStackGrowthDirectionUp() const {
345 bool hasSubsectionsViaSymbols() const { return HasSubsectionsViaSymbols; }
347 // Data directive accessors.
349 const char *getData8bitsDirective() const {
350 return Data8bitsDirective;
352 const char *getData16bitsDirective() const {
353 return Data16bitsDirective;
355 const char *getData32bitsDirective() const {
356 return Data32bitsDirective;
358 const char *getData64bitsDirective() const {
359 return Data64bitsDirective;
361 const char *getGPRel64Directive() const { return GPRel64Directive; }
362 const char *getGPRel32Directive() const { return GPRel32Directive; }
364 /// getNonexecutableStackSection - Targets can implement this method to
365 /// specify a section to switch to if the translation unit doesn't have any
366 /// trampolines that require an executable stack.
367 virtual const MCSection *getNonexecutableStackSection(MCContext &Ctx) const{
371 virtual const MCExpr *
372 getExprForPersonalitySymbol(const MCSymbol *Sym,
374 MCStreamer &Streamer) const;
376 virtual const MCExpr *
377 getExprForFDESymbol(const MCSymbol *Sym,
379 MCStreamer &Streamer) const;
381 bool usesSunStyleELFSectionSwitchSyntax() const {
382 return SunStyleELFSectionSwitchSyntax;
385 bool usesELFSectionDirectiveForBSS() const {
386 return UsesELFSectionDirectiveForBSS;
389 bool needsDwarfSectionOffsetDirective() const {
390 return NeedsDwarfSectionOffsetDirective;
395 bool hasMachoZeroFillDirective() const { return HasMachoZeroFillDirective; }
396 bool hasMachoTBSSDirective() const { return HasMachoTBSSDirective; }
397 bool hasStaticCtorDtorReferenceInStaticMode() const {
398 return HasStaticCtorDtorReferenceInStaticMode;
400 bool getLinkerRequiresNonEmptyDwarfLines() const {
401 return LinkerRequiresNonEmptyDwarfLines;
403 unsigned getMaxInstLength() const {
404 return MaxInstLength;
406 unsigned getMinInstAlignment() const {
407 return MinInstAlignment;
409 bool getDollarIsPC() const {
412 const char *getSeparatorString() const {
413 return SeparatorString;
416 /// This indicates the column (zero-based) at which asm comments should be
418 unsigned getCommentColumn() const {
422 const char *getCommentString() const {
423 return CommentString;
425 const char *getLabelSuffix() const {
429 const char *getDebugLabelSuffix() const {
430 return DebugLabelSuffix;
432 const char *getPrivateGlobalPrefix() const {
433 return PrivateGlobalPrefix;
435 bool hasLinkerPrivateGlobalPrefix() const {
436 return LinkerPrivateGlobalPrefix[0] != '\0';
438 const char *getLinkerPrivateGlobalPrefix() const {
439 if (hasLinkerPrivateGlobalPrefix())
440 return LinkerPrivateGlobalPrefix;
441 return getPrivateGlobalPrefix();
443 const char *getInlineAsmStart() const {
444 return InlineAsmStart;
446 const char *getInlineAsmEnd() const {
449 const char *getCode16Directive() const {
450 return Code16Directive;
452 const char *getCode32Directive() const {
453 return Code32Directive;
455 const char *getCode64Directive() const {
456 return Code64Directive;
458 unsigned getAssemblerDialect() const {
459 return AssemblerDialect;
461 bool doesAllowAtInName() const {
462 return AllowAtInName;
464 bool doesSupportDataRegionDirectives() const {
465 return UseDataRegionDirectives;
467 const char *getZeroDirective() const {
468 return ZeroDirective;
470 const char *getAsciiDirective() const {
471 return AsciiDirective;
473 const char *getAscizDirective() const {
474 return AscizDirective;
476 bool getAlignmentIsInBytes() const {
477 return AlignmentIsInBytes;
479 unsigned getTextAlignFillValue() const {
480 return TextAlignFillValue;
482 const char *getGlobalDirective() const {
483 return GlobalDirective;
485 bool hasSetDirective() const { return HasSetDirective; }
486 bool hasAggressiveSymbolFolding() const {
487 return HasAggressiveSymbolFolding;
489 bool getCOMMDirectiveAlignmentIsInBytes() const {
490 return COMMDirectiveAlignmentIsInBytes;
492 LCOMM::LCOMMType getLCOMMDirectiveAlignmentType() const {
493 return LCOMMDirectiveAlignmentType;
495 bool hasDotTypeDotSizeDirective() const {return HasDotTypeDotSizeDirective;}
496 bool hasSingleParameterDotFile() const { return HasSingleParameterDotFile; }
497 bool hasIdentDirective() const { return HasIdentDirective; }
498 bool hasNoDeadStrip() const { return HasNoDeadStrip; }
499 const char *getWeakRefDirective() const { return WeakRefDirective; }
500 bool hasWeakDefDirective() const { return HasWeakDefDirective; }
501 bool hasWeakDefCanBeHiddenDirective() const {
502 return HasWeakDefCanBeHiddenDirective;
504 bool hasLinkOnceDirective() const { return HasLinkOnceDirective; }
506 MCSymbolAttr getHiddenVisibilityAttr() const { return HiddenVisibilityAttr;}
507 MCSymbolAttr getHiddenDeclarationVisibilityAttr() const {
508 return HiddenDeclarationVisibilityAttr;
510 MCSymbolAttr getProtectedVisibilityAttr() const {
511 return ProtectedVisibilityAttr;
513 bool hasLEB128() const {
516 bool doesSupportDebugInformation() const {
517 return SupportsDebugInformation;
519 bool doesSupportExceptionHandling() const {
520 return ExceptionsType != ExceptionHandling::None;
522 ExceptionHandling::ExceptionsType getExceptionHandlingType() const {
523 return ExceptionsType;
525 bool isExceptionHandlingDwarf() const {
527 (ExceptionsType == ExceptionHandling::DwarfCFI ||
528 ExceptionsType == ExceptionHandling::ARM ||
529 ExceptionsType == ExceptionHandling::Win64);
531 bool doesDwarfUseRelocationsAcrossSections() const {
532 return DwarfUsesRelocationsAcrossSections;
534 bool doDwarfFDESymbolsUseAbsDiff() const {
535 return DwarfFDESymbolsUseAbsDiff;
537 bool useDwarfRegNumForCFI() const {
538 return DwarfRegNumForCFI;
540 bool useParensForSymbolVariant() const {
541 return UseParensForSymbolVariant;
544 void addInitialFrameState(const MCCFIInstruction &Inst) {
545 InitialFrameState.push_back(Inst);
548 const std::vector<MCCFIInstruction> &getInitialFrameState() const {
549 return InitialFrameState;
552 /// Return true if assembly (inline or otherwise) should be parsed.
553 bool useIntegratedAssembler() const { return UseIntegratedAssembler; }
555 /// Set whether assembly (inline or otherwise) should be parsed.
556 virtual void setUseIntegratedAssembler(bool Value) {
557 UseIntegratedAssembler = Value;
560 bool compressDebugSections() const { return CompressDebugSections; }
562 void setCompressDebugSections(bool CompressDebugSections) {
563 this->CompressDebugSections = CompressDebugSections;